This invention relates to a pourable shortening having excellent frying and baking characteristics that, with the addition of emulsifiers, is useful as an all-purpose shortening. More particularly, the present invention relates to an improved process for making a stable pourable shortening without first melting and recrystallizing substantially all of the solid fatty glyceride particles and to the resulting product. The pourable shortening of the present invention has a pumpable consistency that is retained at ambient temperature after storage for extended periods over a temperature range of about 0.degree. F. to about 100.degree. F.
Plastic shortenings are typically used for a variety of baking and frying applications. Such shortenings are non-fluid and are generally prepared from liquid glyceride oils by incorporating therein or forming in situ desired amounts of triglycerides that are normally solid at room temperatures. Typically, the liquid glyceride oils are blended with molten triglycerides which, after the application of suitable cooling procedures, form a non-fluid plastic mass.
However, shortening compositions that have a fluid consistency so that they can be easily pumped, readily dispersed, measured by volume rather than by weight, and more readily mixed with the other constituents for baking without undue labor are increasingly preferred. These fluid shortenings typically comprise suspensions of the normally solid triglycerides in the normally liquid glyceride portion.
One requirement for a marketable pourable shortening is that the solid particles be evenly distributed throughout the liquid phase and remain so for extended periods of time over an extended temperature range without settling out. However, a recurring problem with known pourable shortenings is the tendency of the solid component to separate from the liquid component over a relatively short period of time, particularly when the shortening is subjected to temperature extremes, e.g., below freezing (32.degree. F.) or above normal room temperatures (e.q., above 72.degree.-78.degree. F.). Another recurring problem is the tendancy of known pourable shortenings to become significantly more viscous after exposure to temperatures above normal room temperature, for example 90.degree.-95.degree. F., and, as a result, to lose their fluidity.
The solid triglycerides typically used in shortenings are known to exhibit polymorphic crystal behavior, i.e., they can exist in various distinct crystalline forms known as, e.q., alpha, beta, and beta-prime. In plastic, non-pourable shortenings, beta-prime crystals are preferred because they tend to be short needle-like crystals that create a fine network of interlacing, but discrete, crystals in which liquid oil is enmeshed. Beta crystals, however, are typically much larger with less tendancy to form cohesive forces among crystals, and do not form an interlacing network. As a result, beta crystals are preferred in a pourable shortening to preserve its fluidity.
The specific crystal form obtained for a solid triglyceride is generally dependant upon the composition of the fat and the temperature and speed at which crystallization takes place. For example, the least stable crystalline forms, generally the alpha and beta-prime forms, tend to form upon rapid chilling of the molten fat component. Transformation of the alpha and beta-prime crystals to the more thermodynamically stable beta form generally occurs over an extended period of time. Most present methods for making pourable shortenings melt all of the solid triglyceride particles by heating them above their melting point and then recrystallizing portions of the triglycerides using votation followed by recycling back into the melted feedstock to cool the entire mass, or by slow, agitated chilling of the entire mass. Both types of methods will yield beta crystals. Still other known pourable shortenings thermally treat the solid triglycerides prior to addition to the liquid oil to insure that the solids exist in the beta phase. These known processes are time-consuming, require additional expenditures of energy resources, are expensive, and require the careful recrystallization of the solid fat particles to insure that they are in the beta phase.
Accordingly, it is an object of this invention to provide a pourable shortening that is convenient to use.
It is another object of this invention to provide a pourable shortening that can be used for frying and pastry baking.
It is a further object of this invention to provide an all-purpose pourable shortening.
It is yet another object of this invention to provide a pourable shortening without melting and recrystallizing all of the solid triglyceride particles.
Another object of this invention is to provide a pourable shortening that is pumpable at ambient temperature after storage over a temperature range from about 0.degree. F. to about 100.degree. F.